IgA antibodies for cancer therapy.

Antibody-based therapy is a new treatment option for selected tumor patients. Today, human IgG(1) is the most widely used isotype, because it effectively activates human complement, recruits NK cells for ADCC, and has an extended plasma half life. In recent work, however, neutrophils--the most populous cytotoxic cells in humans--were more effectively recruited by human IgA than by IgG antibodies. IgA antibodies may have the additional advantages of forming natural dimers with improved signaling capacity on tumor cells, and being actively transported into mucosal secretions with the potential for improved targeting of certain carcinomas from the luminal surface.